Geoelectric studies of the oil and gas bearing area on the southern slope of the central Dnieper-Donets Basin part

Abstract

In 2017 modern synchronous magnetotelluric and magnetovariational investigations were carried out on the Nesseno-Irzhuets—Abramovka profiles in eleven points for the study of the deep structure of the central part of the southern Dnipro-Donets Basin (DDB) board, where the Kirovograd electrical conduction anomaly crosses the Lokhvytsky and Poltava blocks of the DDB. The processing of experimental materials was carried out using known programs PRC_MTMV and PTS. Reliable estimates of the types for periods of geomagnetic variations from 30 to 3700 s and parameters of apparent electrical resistance (amplitude values and phase of impedance) from 40 to 10 000 s are obtained. A joint analysis of complex types and curves of apparent electrical resistance and impedance phases indicates the presence of a surface conductor. Which extends from northwest to southeast and associated with superficial conductivity of the sedimentary strata of the DDB. Also spatially detailed heterogeneity, which is assumed in deep horizons with an upper edge of 20—30 km in the middle part of the profile and corresponds to Kirovograd electrical conduction anomaly. The qualitative interpretation of experimental MT/MV data allows us to clarify the perspective on the oil and gas bearing area in the area of the southern side, which outlines the central part of the DDB between the settlements of Khorol and Reshetilivka. In addition, confirm and detail previously allocated oil and gas prospecting sites, namely Glydinintsiv, with which the anomaly is connected in its southeastern part and extend to the southeast by 20 km. Information about the existence of a deep conductor and its parameters should be the basis for quantitative interpretation and construction of 3D deep geoelectric model.